Inequality of health attributed to race/ethnicity and socioeconomic status (SES) continues to be a problem in the U.S. population, especially as manifested in racial/ethnic differences in the prevalence, morbidity and mortality from obesity and nutrition-related diseases. As gaps in health continue to widen, it is imperative to identify the determinants of the differential distribution of these diseases across race/ethnic groups. This proposed work will examine the impact of SES on longitudinal patterns of inactivity and obesity, with the primary goal of determining how these longitudinal relationships vary by race/ethnicity across the transition from adolescence to adulthood, a period during which major race/ethnic differences in obesity become apparent, and when adult lifestyle behaviors are solidified. The life course perspective will inform descriptive and multivariate modeling analyses of the relative influence of parental vs. young adult SES factors on young adult inactivity patterns as well as dynamic shifts in those patterns using data from the National Longitudinal Study of Adolescent Health. Ultimately, structural equation modeling will be used to follow the pathway from SES and race/ethnicity to inactivity and finally to obesity over the transition to adulthood.